GD incident on 2018-03-22 — NV

Operator
Nv Energy
Cause
Excavation Issue
Commodity
Natural Gas
Program
GD
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$20
Incident datetime
2018-03-22 20:25
Report number
Location
NV, WASHOE
Narrative
On march 22, 2018 at 20:17, the reno fire department was notified of a building fire at 624 eureka avenue in reno, nevada. At 20:25 nv energy (nve) was contacted by the city of reno public safety dispatch notifying of a "working fire" at 624 eureka avenue in reno, nevada. Nve gas dispatch sends gas servicemen to investigate. At 20:51 the city of reno public safety dispatch contacted nve again to report that there was an explosion at this location, possibly from the furnace. At 21:02 the first nve personnel arrive at the site and found the home at 624 eureka ave damaged by what appeared to be a gas explosion with indications of underground gas readings. Reno fire department and nve personnel evacuate the neighborhood and monitor gas concentrations while other nve personnel expose the service tee and secure the gas leak. The leak occurred at the threaded joint between a 3/4" black iron pipe nipple and a 3/4" black iron 90 degree elbow at the service tee connection to 614 eureka avenue. Based upon the reno fire department incident report, natural gas leaking from the service tee appears to have traveled through a service trench into the basement of 624 eureka. The leaking gas was ignited in the basement by the furnace, exploded, and damaged the home. Two individuals were in the residence at the time of the explosion but no injuries were sustained. The cause of the failure is still under investigation and a supplemental report will be filed when the cause is determined. At 22:36 the nve duty supervisor on scene determined that the property damage costs would exceed $50,000. The initial notification to the national response center (nrc) was made at 22:49 and was given nrc incident report # 1207485. Nve provided an update to the nrc on march 23, 2018 at 15:44 and was given nrc incident report # 1207546. Supplemental update: further analysis has determined that the pipe-to-elbow joint failed due to overload from an external bending load and not due to a material or manufacturing defect associated with the pipes or fittings. The external bending load at the failed pipe-to-elbow joint occurred as a result of loading imparted to this joint during compaction around the temporary service connection. Nv energy's contractor was performing backfill and compaction activities on this temporary service connection one day prior to the incident occurring. Final update: analysis has concluded and the incident was caused by a leak from a crack in the black iron pipe used for the temporary service connection for the neighboring property 614 eureka avenue. The gas migrated into the basement of the incident house where it found an ignition source, most likely the house furnace. The direct cause of the crack in the pipe was mechanical overloading of the horizontal section of the temporary service connection. The mechanical overloading was likely caused during compaction of sand around the temporary service connection, due to insufficient cover (sand above the pipe) during compaction.
Detailed record list
Occurred At
2018-03-22 20:25:00
Year
2018
Report Received Date
2018-04-19 00:00:00
Iyear
2018.0
Report Number
20180043.0
Supplemental Number
31394.0
Report Type
Supplemental Final
Operator Id
Name
Nv Energy
Operator Street Address
Po Box 10100
Operator City Name
Reno Washoe
Operator State Abbreviation
NV
Operator Postal Code
89520
Local Datetime
2018-03-22 20:17:00
Location Street Address
624 Eureka Avenue
Location City Name
Reno
Location County Name
Washoe
Location State Abbreviation
NV
Location Postal Code
89512
Location Latitude
Location Longitude
Nrc Rpt Datetime
2018-03-22 22:49:00
Nrc Rpt Num
Commodity Released Type
Natural Gas
Unintentional Release
54.0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Ignite Ind
Yes
Explode Ind
Yes
Num Pub Evacuated
30.0
Incident Identified Datetime
2018-03-22 20:25:00
On Site Datetime
2018-03-22 21:02:00
Federal
No
Location Type
Public Property
Incident Area Type
Underground
Incident Area Subtype
Under Pavement
Depth Of Cover
20.0
Crossing
No
Pipe Facility Type
Investor Owned
System Part Involved
Service
Installation Year
2018.0
Pipe Diameter
0.75
Pipe Specification
Astm A197 & Astm A53
Pipe Manufacturer
Unknown
Material Involved
Other
Material Details
Black Iron
Release Type
Leak
Leak Type
Connection Failure
Class Location Type
Class 3 Location
Est Cost Oper Paid
322526.0
Est Cost Prop Damage
20.0
Est Cost Emergency
25646.0
Est Cost Other
4500.0
Est Cost Other Details
Compensation For Evacuees
Est Cost Unintentional Release
261.0
Prpty
352953.0
Commercial Affected
0.0
Industrial Affected
0.0
Residences Affected
1.0
Accident Psig
37.0
Normal Psig
37.0
Mop Psig
40.0
Accident Pressure
Pressure Did Not Exceed Maop
Scada In Place Ind
No
Accident Identifier
Notification From Emergency Responder
Investigation Status
No, the facility was not monitored by a controller(s) at the time of the incident
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Excavation Damage
Cause Details
Excavation Damage By Operator's Contractor (Second Party)
Ex Party Type
Excavation Damage By Operator's Contractor (Second Party)
Notify Cga Dirt
No
Public Row Ind
Yes
Public Subtype
City Street
Excavator Type
Contractor
Excavator Equipment
Unknown/other
Work Performed
Natural Gas
One Call Notified Ind
Yes
One Call Ticket Num
802900026
Locator Type
Contract Locator
Visible Marks
Yes
Service Interruption
Yes
Service Interruption Hours
14.0
Root Cause Category
Excavation Issue
Root Cause Type
Improper Backfilling Practices
Preparer Name
J** W******
Preparer Title
Manager Gas Ops And Compliance
Preparer Email
J*******@n*******.com
Preparer Telephone
775-834-7850
Authorizer Name
J** W******
Authorizer Title
Manager Gas Ops And Compliance
Authorizer Telephone
775-834-7850
Authorizer Email
J*******@n*******.com
Narrative
On march 22, 2018 at 20:17, the reno fire department was notified of a building fire at 624 eureka avenue in reno, nevada. At 20:25 nv energy (nve) was contacted by the city of reno public safety dispatch notifying of a "working fire" at 624 eureka avenue in reno, nevada. Nve gas dispatch sends gas servicemen to investigate. At 20:51 the city of reno public safety dispatch contacted nve again to report that there was an explosion at this location, possibly from the furnace. At 21:02 the first nve personnel arrive at the site and found the home at 624 eureka ave damaged by what appeared to be a gas explosion with indications of underground gas readings. Reno fire department and nve personnel evacuate the neighborhood and monitor gas concentrations while other nve personnel expose the service tee and secure the gas leak. The leak occurred at the threaded joint between a 3/4" black iron pipe nipple and a 3/4" black iron 90 degree elbow at the service tee connection to 614 eureka avenue. Based upon the reno fire department incident report, natural gas leaking from the service tee appears to have traveled through a service trench into the basement of 624 eureka. The leaking gas was ignited in the basement by the furnace, exploded, and damaged the home. Two individuals were in the residence at the time of the explosion but no injuries were sustained. The cause of the failure is still under investigation and a supplemental report will be filed when the cause is determined. At 22:36 the nve duty supervisor on scene determined that the property damage costs would exceed $50,000. The initial notification to the national response center (nrc) was made at 22:49 and was given nrc incident report # 1207485. Nve provided an update to the nrc on march 23, 2018 at 15:44 and was given nrc incident report # 1207546. Supplemental update: further analysis has determined that the pipe-to-elbow joint failed due to overload from an external bending load and not due to a material or manufacturing defect associated with the pipes or fittings. The external bending load at the failed pipe-to-elbow joint occurred as a result of loading imparted to this joint during compaction around the temporary service connection. Nv energy's contractor was performing backfill and compaction activities on this temporary service connection one day prior to the incident occurring. Final update: analysis has concluded and the incident was caused by a leak from a crack in the black iron pipe used for the temporary service connection for the neighboring property 614 eureka avenue. The gas migrated into the basement of the incident house where it found an ignition source, most likely the house furnace. The direct cause of the crack in the pipe was mechanical overloading of the horizontal section of the temporary service connection. The mechanical overloading was likely caused during compaction of sand around the temporary service connection, due to insufficient cover (sand above the pipe) during compaction.
Occurred At 2018-03-22 20:25:00
Year 2018
Report Received Date 2018-04-19 00:00:00
Iyear 2018.0
Report Number 20180043.0
Supplemental Number 31394.0
Report Type Supplemental Final
Operator Id 18308 PHMSA Enforcement
Name Nv Energy
Operator Street Address Po Box 10100
Operator City Name Reno Washoe
Operator State Abbreviation NV
Operator Postal Code 89520
Local Datetime 2018-03-22 20:17:00
Location Street Address 624 Eureka Avenue
Location City Name Reno
Location County Name Washoe
Location State Abbreviation NV
Location Postal Code 89512
Location Latitude 39.534873 Google Maps OpenStreetMap
Location Longitude -119.804895 Google Maps OpenStreetMap
Nrc Rpt Datetime 2018-03-22 22:49:00
Nrc Rpt Num 1207485 NRC Report How to search
Commodity Released Type Natural Gas
Unintentional Release 54.0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Ignite Ind Yes
Explode Ind Yes
Num Pub Evacuated 30.0
Incident Identified Datetime 2018-03-22 20:25:00
On Site Datetime 2018-03-22 21:02:00
Federal No
Location Type Public Property
Incident Area Type Underground
Incident Area Subtype Under Pavement
Depth Of Cover 20.0
Crossing No
Pipe Facility Type Investor Owned
System Part Involved Service
Installation Year 2018.0
Pipe Diameter 0.75
Pipe Specification Astm A197 & Astm A53
Pipe Manufacturer Unknown
Material Involved Other
Material Details Black Iron
Release Type Leak
Leak Type Connection Failure
Class Location Type Class 3 Location
Est Cost Oper Paid 322526.0
Est Cost Prop Damage 20.0
Est Cost Emergency 25646.0
Est Cost Other 4500.0
Est Cost Other Details Compensation For Evacuees
Est Cost Unintentional Release 261.0
Prpty 352953.0
Commercial Affected 0.0
Industrial Affected 0.0
Residences Affected 1.0
Accident Psig 37.0
Normal Psig 37.0
Mop Psig 40.0
Accident Pressure Pressure Did Not Exceed Maop
Scada In Place Ind No
Accident Identifier Notification From Emergency Responder
Investigation Status No, the facility was not monitored by a controller(s) at the time of the incident
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Excavation Damage
Cause Details Excavation Damage By Operator's Contractor (Second Party)
Ex Party Type Excavation Damage By Operator's Contractor (Second Party)
Notify Cga Dirt No
Public Row Ind Yes
Public Subtype City Street
Excavator Type Contractor
Excavator Equipment Unknown/other
Work Performed Natural Gas
One Call Notified Ind Yes
One Call Ticket Num 802900026
Locator Type Contract Locator
Visible Marks Yes
Service Interruption Yes
Service Interruption Hours 14.0
Root Cause Category Excavation Issue
Root Cause Type Improper Backfilling Practices
Preparer Name J** W******
Preparer Title Manager Gas Ops And Compliance
Preparer Email J*******@n*******.com
Preparer Telephone 775-834-7850
Authorizer Name J** W******
Authorizer Title Manager Gas Ops And Compliance
Authorizer Telephone 775-834-7850
Authorizer Email J*******@n*******.com
Narrative On march 22, 2018 at 20:17, the reno fire department was notified of a building fire at 624 eureka avenue in reno, nevada. At 20:25 nv energy (nve) was contacted by the city of reno public safety dispatch notifying of a "working fire" at 624 eureka avenue in reno, nevada. Nve gas dispatch sends gas servicemen to investigate. At 20:51 the city of reno public safety dispatch contacted nve again to report that there was an explosion at this location, possibly from the furnace. At 21:02 the first nve personnel arrive at the site and found the home at 624 eureka ave damaged by what appeared to be a gas explosion with indications of underground gas readings. Reno fire department and nve personnel evacuate the neighborhood and monitor gas concentrations while other nve personnel expose the service tee and secure the gas leak. The leak occurred at the threaded joint between a 3/4" black iron pipe nipple and a 3/4" black iron 90 degree elbow at the service tee connection to 614 eureka avenue. Based upon the reno fire department incident report, natural gas leaking from the service tee appears to have traveled through a service trench into the basement of 624 eureka. The leaking gas was ignited in the basement by the furnace, exploded, and damaged the home. Two individuals were in the residence at the time of the explosion but no injuries were sustained. The cause of the failure is still under investigation and a supplemental report will be filed when the cause is determined. At 22:36 the nve duty supervisor on scene determined that the property damage costs would exceed $50,000. The initial notification to the national response center (nrc) was made at 22:49 and was given nrc incident report # 1207485. Nve provided an update to the nrc on march 23, 2018 at 15:44 and was given nrc incident report # 1207546. Supplemental update: further analysis has determined that the pipe-to-elbow joint failed due to overload from an external bending load and not due to a material or manufacturing defect associated with the pipes or fittings. The external bending load at the failed pipe-to-elbow joint occurred as a result of loading imparted to this joint during compaction around the temporary service connection. Nv energy's contractor was performing backfill and compaction activities on this temporary service connection one day prior to the incident occurring. Final update: analysis has concluded and the incident was caused by a leak from a crack in the black iron pipe used for the temporary service connection for the neighboring property 614 eureka avenue. The gas migrated into the basement of the incident house where it found an ignition source, most likely the house furnace. The direct cause of the crack in the pipe was mechanical overloading of the horizontal section of the temporary service connection. The mechanical overloading was likely caused during compaction of sand around the temporary service connection, due to insufficient cover (sand above the pipe) during compaction.

All rights reserved. Copyright © by ClearPHMSA